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Biomedical subjects

S P Bhat

Publications and source records attributed to S P Bhat.

At least 37 records · Page 2Linked to original sources
PubMed1989

Human fetal lens epithelial cells in culture: an in vitro model for the study of crystallin expression and lens differentiation.

We have cultured and passaged human fetal lens epithelial cells. Cultured cells exhibited hexagonal, cuboidal shape typical of epithelial cells. Unlike previous observations made with cultured mammalian lens epithelial cells, indirect immunofluorescence and temporal analysis of 35S-labeled proteins demonstrated undiminished levels of alpha B-crystallin in primary, secondary, and tertiary cultures. Among the alpha-crystallins only alpha B synthesis was detected. Two dimensional gel electrophoresis indicated the presence of alpha B2 and no alpha B1. beta B2-crystallin, a fiber cell specific protein hardly detectable in primary cultures, increased significantly upon passaging. Human fetal lens epithelial cell cultures, described in this report, thus present a useful in vitro model for the study of lens epithelial cell differentiation and its pathological manifestations.

Biomarkers↗
PubMed1988

Use of "submarine" gel electrophoresis for running multiple two-dimensional protein gels.

An apparatus commonly used for the electrophoresis of submerged agarose gels was used to separate proteins in the second dimension, after isoelectric focusing in the first dimension. Multiple second-dimension gels were stacked one above the other and run horizontally, submerged in the sodium dodecyl sulfate-containing Laemmli buffer system. The reproducibility of the gels run under these conditions is remarkable and eliminates the need for individual vertical electrophoresis units for routine analysis. The units for submerged horizontal gel electrophoresis are easily made or are inexpensively available commercially.

Electrophoresis, Polyacrylamide Gel↗
PubMed1988

Maintenance of the synthesis of alpha B-crystallin and progressive expression of beta Bp-crystallin in human fetal lens epithelial cells in culture.

We have cultured and maintained human fetal lens epithelial cells for several months in primary, secondary, and tertiary culture(s). These cells show unabated synthesis of alpha B-crystallin (alpha B), a lens epithelial cell-specific marker, and progressive expression of beta Bp-crystallin (beta Bp), a major polypeptide of the differentiated lens fiber cells in vivo. Interestingly, the expression of beta Bp was found to be dependent on subculturing of the cells and not on the age of cultures. These observations demonstrate that human fetal lens epithelial cells can be cultured in vitro without the loss of lens specific characteristics and with commitment to differentiation at the biochemical level.

Blotting, Western↗
PubMed1988

Genetic linkage analysis of autosomal dominant congenital cataracts with lens-specific DNA probes and polymorphic phenotypic markers.

The authors studied a four-generation family with autosomal dominant congenital cataracts (ADCCs) using linkage analysis with 23 polymorphic phenotypic markers and DNA restriction fragment length polymorphisms (RFLPs) detected by lens-specific DNA probes. A total of 19 family members were studied and the ten affected members had embryonal lens opacities. Close linkage was rejected with DNA probes encoding beta-crystallin, gamma-crystallin, and the major intrinsic protein of the lens fiber membrane (MIP) excluding defects of these genes as the cause of the cataract in this family. No statistically significant lod scores were produced with the polymorphic phenotypic markers. These results support the genetic heterogeneity of ADCCs.

Aquaporins↗
PubMed1986

Differential protein synthesis in steroid-treated ocular surface epithelium.

Topical prednisolone and cortexolone, a known glucocorticoid receptor antagonist, differentially affected the synthesis of proteins in normal corneal epithelium and migrating conjunctival epithelium after complete corneal deepithelialization, as measured by 35S-methionine incorporation and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel) electrophoresis. Application of either prednisolone or cortexolone to corneal epithelium resulted in similar protein synthesis patterns, each showing two new protein bands of about 15K and 32K. Cortexolone, but not prednisolone, initiated the appearance of several protein bands of different molecular weights in the migrating conjunctival epithelium, while treatment with prednisolone plus cortexolone resulted in a pattern of protein bands which resembled the saline-treated control. Crude extracts of prednisolone-treated migrating epithelium also enhanced the inhibition of phospholipase A2 activity, and this prednisolone-induced inhibition was reversed by cortexolone.

17-Hydroxycorticosteroids↗
PubMed1984

A simple method to characterize gamma-crystallin synthesized in vitro.

Investigation of the migration of in vitro synthesized gamma-crystallin which has not been heat denatured on polyacrylamide gel electrophoresis in presence of sodium dodecyl sulfate indicates that this class of proteins behaves in an anomalous manner. While other in vitro synthesized lens proteins under these conditions migrate as theoretically expected, gamma-crystallin is retarded, having a mobility comparable to a 92 000 dalton component. Only upon heat denaturation does this protein fraction migrate as a 20 000 dalton species. Since other in vitro synthesized lens proteins have molecular weights of approximately 20 000 daltons, it is only with this methodology that gamma-crystallin synthesis can be unequivocally followed in a simple, rapid, one-dimensional fractionation system.

Animals↗
PubMed1984

Complete nucleotide sequence of a cDNA derived from calf lens gamma-crystallin mRNA: presence of Alu I-like DNA sequences.

The nucleotide sequence of a cloned cDNA derived from gamma-crystallin mRNA of calf lens was determined. The cloned cDNA contains the entire coding region 522 bp long, 30 nucleotides of the 5' noncoding region, and 67 residues in the 3' noncoding region followed by a poly(A) tail of 25 nucleotides. The deduced amino acid sequence directly demonstrates for the first time that the calf gamma-crystallin contains 174 residues. The nucleotide sequence contains a number of interesting features including a 32-bp sequence in the 3' region with 70% complementarity to the 3' end of the first monomer unit of the consensus Alu I DNA. Within this region, a 32-bp sequence shows about 80% homology with a segment of hamster 4.5S RNA. The possible evolutionary and regulatory significance of these sequences is discussed.

Amino Acid Sequence↗
PubMed1980

Chicken lens crystallin DNA sequences show at least two delta-crystallin genes.

Restriction analysis of chicken DNA using probes derived from a cloned cDNA and analysis of cloned genomic DNA fragments containing delta-crystallin gene sequences have indicated the presence of at least two non-allelic genes for delta-crystallin, the first and principal crystallin synthesised in the embryonic chicken lens. Electron microscopic analyses of three cloned genomic fragments revealed that the delta-crystallin mRNA gene sequences are interrupted at least 14 times in one of the delta-crystallin genes.

Animals↗
PubMed1980

Comparison of two delta-crystallin genes in the chicken.

Restriction endonuclease mapping and electron microscopy established that there are at least two nonallelic delta-crystallin genes in the chicken. The structure of a complete delta-crystallin gene has been deduced by analysis of five cloned fragments from the chicken genome. Fifteen intervening sequences compose approximately 80% of this gene; the other gene contains at least 14 intervening sequences. The mRNA gene sequences appear to be similar; at least 60% divergence was found between the intervening sequences of the two delta-crystallin genes. Insertions or deletions or both appear to be major events responsible for these differences.

Animals↗
PubMed1979

Molecular cloning and partial characterization of delta-crystallin cDNA sequences in a bacterial plasmid.

Double-stranded cDNA synthesized from delta-crystallin mRNA isolated from lens fiber cells of 15-day-old embryonic chicken was cloned in Escherichia coli chi 1776 in the Pst I site of the plasmid pBR322 by using the oligo(dC) . oligo(dG) joining procedure. Twelve Amps Tetr transformants contained sequences complementary to purified delta-crystallin [32P]cDNA. One of the recombinant clones (p delta Cr-2) had an insert of 1241 +/- 240 base pairs, as judged by R-looping analysis with purified delta-crystallin mRNA. The inserted cDNA represents at least 69% of the delta-crystallin coding sequences. p delta Cr-2 was further characterized by restriction analysis, protection of delta-crystallin [3H]cDNA from digestion by S1 nuclease, and hybrid-mediated arrest of delta-crystallin mRNA translation in vitro. p delta Cr-2 provides an invaluable probe for additional analysis of the primary structure, gene organization, and regulated synthesis of delta-crystallin, the principal protein synthesized during lens differentiation in the chicken embryo.

Animals↗
PubMedDate not supplied

Recurrent respiratory papillomatosis.

Recurrent respiratory papillomatosis is characterized by the appearance of benign laryngeal squamous papillomas in childhood. Lung involvement is rare. We report a case of childhood laryngeal papillomas who developed tracheobronchial papillomas and a nodule in the lung after a period of 21 years. Frequent sampling of pulmonary lesions to detect malignant transformation is suggested as prognosis of lung lesions are worse in comparison to laryngeal papillomas.

Adult↗
PubMedDate not supplied

Urinothorax: a case report.

A case of right sided transudative pleural effusion associated with right sided renal calculi and moderate hydronephrosis is reported. The diagnosis of urinothorax was confirmed by demonstrating a pleural fluid to serum creatinine ratio of greater than one. The relief of obstructive uropathy by surgical treatment of renal calculi resulted in resolution of the pleural effusion.

Creatinine↗